1. Field of the Invention
The present invention relates to heat exchangers of the type which are positionable so as to be in a heat exchange relationship with a flowing gaseous medium, and which include tubular coils positioned between spaced apart supporting walls.
2. Description of the Prior Art
Conventional heat exchangers of the type which are positionable in the flow of a working medium generally utilize as supporting walls for the tubular coils therein which carry the liquid medium to be heated or cooled, two spaced apart supporting plates which are provided with a number of holes through which the tubular coils are extended. To enable mounting, the tubular coils must be divided up so that they can be fitted through the holes in the plates, and thereafter they are joined together, e.g., by welding. The welding work is expensive and requires careful and cost-demanding control so that the tubular strength requirements are met, e.g., because the tubes are often heavily loaded by the working medium.
Another conventional type of heat exchanger utilizes as tube supporting means a multiplicity of rods which are attached together at their upper ends and which are provided at their lower ends with suspension devices to which the tubular coils can be mounted. However, with this system when the external working medium flows in a vertical direction, the suspension devices and the collecting vessels will be positioned in the flow path which will in fact disturb it, and, furthermore, if the medium flow comprises a very hot gas and flows from top to bottom through the exchanger, the suspension devices will also become very hot. In these situations a separate cooling medium such as water will be required to cool the suspension devices (so that they can maintain their strength properties), and such a set up complicates the entire heat exchanger construction. Heat exchangers of this type normally are used to heat up and evaporate water which is flowing through the tubular coils by means of a hot gas.
It is thus an object of the present invention to provide an improved heat exchanger in which the tubular coils are supported in a fashion which avoids the disadvantages of the prior art supporting structures.